Warehousing and order fulfillment systems and methods

ABSTRACT

Warehouse automation and methods of controlling material flow can be used to streamline order fulfillment. For example, according to some embodiments described herein, a method includes: causing a first mobile robot to engage with and transport a mobile storage unit to a robotic picking cell, causing a second mobile robot to engage with and transport an outbound container to the robotic picking cell, and causing the picking robot to transfer a sellable unit from the mobile storage unit to the outbound container.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 62/589,291, filed Nov. 21, 2017. The disclosure of the priorapplication is considered part of (and is incorporated by reference in)the disclosure of this application.

TECHNICAL FIELD

This document relates to systems and methods for enhancing efficienciesof order fulfillment processes. For example, this document relates towarehouse automation and methods of controlling material flow tostreamline order fulfillment processes.

BACKGROUND

Very few things can alienate a customer more than not having their orderfulfilled properly and promptly. Two-day deliveries are currentlystandard, and customers are often willing to pay extra for same-day ornext-day deliveries. Highly efficient warehousing, order assemblage, andshipping processes are on the frontline of meeting these high level ofcustomer expectations.

The order fulfillment process refers to all the steps companies takefrom when they receive a customer order (which can include an order thatis wholly or partly internal to the company, such as a storereplenishment order) until the items are landed in customers' hands.Such steps can include, for example: the order is sent to the warehouse;a worker goes into the warehouse, finds the items in the order, andpicks the items off the shelf; the order is packed for shipping; theorder is shipped.

The use of warehouse automation is one way to increase the efficiency ofan order fulfillment process. The goal of automation is to cut outmanual steps of the order fulfillment process. Automation technology isuseful for at least two reasons: to help reduce the occurrences of humanerror, and to make processes more efficient.

SUMMARY

This document describes systems and methods for enhancing efficienciesof order fulfillment processes. For example, this document describeswarehouse automation and methods of controlling material flow tostreamline and expedite order fulfillment processes in a cost-effectivemanner.

In one aspect, this disclosure is directed to an order fulfillmentsystem that includes a dense inventory storage system, an automatedorder assemblage system, and a control system. The dense inventorystorage system can include: a plurality of robotically-movable and/ormanually-movable mobile storage units consolidated in an area (eachmobile storage unit can define one or more storage locations); aplurality of sellable unit containers (each sellable unit container canbe located in a respective one of the storage locations); and aplurality of differing types of sellable units (each sellable unitcontainer containing one or more of a single type of the sellable units,or of two or more types of sellable units). The automated orderassemblage system can include: one or more first mobile robots that eachreleasably engage and transport any individual mobile storage unit; oneor more second mobile robots that each releasably engage and transportany individual sellable unit container; a plurality of outboundcontainers; one or more third mobile robots that each releasably engageand transport any individual outbound container; and a robotic pickingcell. The robotic picking cell can be adapted to receive: (i) individualsecond mobile robots transporting an engaged sellable unit container and(ii) individual third mobile robots transporting an engaged outboundcontainer. The robotic picking cell can include a picking robotconfigured to transfer one or more individual sellable units from arespective one of the sellable unit containers in the robotic pickingcell to a respective one of the outbound containers in the roboticpicking cell. The control system can be operable, in response toreceiving an order for a particular sellable unit of the sellable units,to: (i) cause one of the first mobile robots to engage and transport aparticular mobile storage unit (the particular mobile storage unitstoring a particular sellable unit container containing the particularsellable unit); (ii) cause one of the second mobile robot to engage andtransport the particular sellable unit container to the robotic pickingcell; and/or (iii) cause the picking robot to transfer the particularsellable unit into a particular outbound container.

Such an order fulfillment process can optionally include one or more ofthe following features. The order fulfillment system may also include anautomated container transfer system configured to transfer individualsellable unit containers from the mobile storage units in preparationfor engagement of the individual sellable unit containers withrespective individual second mobile robots. The order fulfillment systemmay also include a conveyance system that inducts the plurality ofsellable unit containers to the dense inventory storage system. Theorder fulfillment system may also include an automated containertransfer system configured to transfer individual sellable unitcontainers from the conveyance system to respective individual storagelocations of the mobile storage units. The control system may be alsooperable, in response to receiving an order for a particular sellableunit of the sellable units, to cause one of the third mobile robots toengage the particular outbound container and to transport the particularoutbound container to the robotic picking cell to receive the particularsellable unit from the picking robot. The order fulfillment system mayalso include an outbound buffer area where multiple ones of the outboundcontainers that are ready for shipment are staged. The control systemmay be also operable to determine an optimized sequence in which themultiple ones of the outbound containers that are ready for shipmentshould be loaded into an outbound trailer. The optimized sequence may bebased on an efficient technique for stocking shelves of a retail store.

In another aspect, this disclosure is directed to a method for preparingfor a shipment of an order that includes a first sellable unit. Themethod can be executed by a control system in response to receiving theorder. The method includes: causing a first mobile robot to engage withand transport a particular mobile storage unit of a plurality ofrobotically-movable mobile storage units located in, or retrieved from,a dense storage area. Each of the mobile storage units may define one ormore storage locations that can each receive a sellable unit container.The particular mobile storage unit can store a first sellable unitcontainer containing the first sellable unit. The method can alsoinclude causing a second mobile robot to engage with and transport thefirst sellable unit container to a robotic picking cell comprising apicking robot. The method can also include causing a third mobile robotto engage with and transport a particular outbound container to therobotic picking cell, and/or causing the picking robot to transfer thefirst sellable unit from the first sellable unit container to theparticular outbound container.

Such a method may optionally include one or more of the followingfeatures. The order may also include a second sellable unit that differsfrom the first sellable unit. The method may also include: causing thesecond mobile robot to transfer the first sellable unit container out ofthe robotic picking cell; causing a fourth mobile robot to engage with asecond sellable unit container containing the second sellable unit andto transport the second sellable unit container to the robotic pickingcell. The method may also include causing the picking robot to transferthe second sellable unit from the second sellable unit container to theparticular outbound container. The method may also include: prior tocausing the picking robot to transfer the second sellable unit from thesecond sellable unit container to the particular outbound container,causing the third mobile robot to transfer the particular outboundcontainer containing the first sellable unit out of the robotic pickingcell, and subsequently causing the third mobile robot or another mobilerobot to transfer the particular outbound container containing the firstsellable unit to the robotic picking cell. The method may also include:prior to causing the picking robot to transfer the second sellable unitfrom the second sellable unit container to the particular outboundcontainer, causing the third mobile robot to keep the particularoutbound container containing the first sellable unit in the roboticpicking cell during: (i) the causing the second mobile robot to transferthe first sellable unit container out of the robotic picking cell and/or(ii) the causing the fourth mobile robot to transport the secondsellable unit container containing the second sellable unit to therobotic picking cell.

In another aspect, this disclosure is directed to an order fulfillmentsystem that includes: (i) a plurality of sellable unit containers; (ii)a plurality of differing types of sellable units, each sellable unitcontainer containing one or more of a single type of the sellable units;(iii) a plurality of outbound containers; (iv) one or more mobilecontainer robots that each releasably engage and transport anyindividual sellable unit container or any individual outbound container;and/or (v) a robotic picking cell comprising a picking robot configuredto transfer one or more individual sellable units from a respective oneof the sellable unit containers in the robotic picking cell to arespective one of the outbound containers in the robotic picking cell.

Such an order fulfillment system may optionally include one or more ofthe following features. The robotic picking cell may be adapted toconcurrently receive: (i) an individual mobile container robottransporting an engaged sellable unit container and/or (ii) anindividual mobile container robot transporting an engaged outboundcontainer. The order fulfillment system may also include: a plurality ofrobotically-movable mobile storage units, each mobile storage unitdefining multiple storage locations, each sellable unit containerlocated in a respective one of the storage locations. The orderfulfillment system may also include one or more mobile shelf robots thateach releasably engage and transport any individual mobile storage unit.The order fulfillment system may also include an automated containertransfer system configured to transfer individual sellable unitcontainers from the mobile storage unit in preparation for engagement ofthe individual sellable unit containers with respective individualmobile container robots.

The systems and processes described here may be used to provide one ormore of the following optional benefits. First, some embodiments providean order fulfillment process that is more responsive and agile so orderscan be shipped to internal and external customers in a shorter timeframethan current processes. Such a result can be accomplished, for example,through optimizing material flow by reducing delays and interferences.Second, some embodiments allow multiple types of orders to be processedand fulfilled using the same (or essentially the same) order fulfillmentprocess. For example, direct-to-customer shipments, store replenishmentorders, customer pick-up-at-store orders, forward deployment ofinventory shipments, inventory transfers, and the like can beadvantageously processed and fulfilled using essentially the sameprocess. Third, inventory carrying costs can be reduced by the addedefficiencies provided by the systems and processes described herein.Fourth, the accuracy of order fulfillment processes can be enhanced byeliminating human errors using the automated systems and processesdescribed herein. Fifth, labor costs associated with the orderfulfillment processes can be reduced using the automated systems andprocesses described herein. Sixth, warehouse space requirements can bereduced using the automated systems and processes described herein.

Other features, aspects and potential advantages will be apparent fromthe accompanying description and figures.

DESCRIPTION OF DRAWINGS

FIG. 1 is a highly-simplified schematic diagram of a basic orderfulfillment process.

FIG. 2 is a flowchart of an example order fulfillment process inaccordance with some embodiments.

Like reference symbols in the various drawings indicate like elements

DETAILED DESCRIPTION

This document describes systems and methods for enhancing efficienciesof order fulfillment processes. For example, this document describes thedaily replenishment and movement of inventory generated from real-timedemand singles for in-store retail sales and direct-to-guest on-linesales fulfilled from a multi-echelon inventory holding model at thecorrect unit of measure, using fast and easy material handling equipmentthat will create operational efficiency at every process step in thesupply chain. Said another way, this document also describes warehouseautomation and methods of controlling material flow to streamline and toconsolidate different types of order fulfillment processes (which caninclude, for example, orders for direct shipments to consumers, ordersthat are wholly or partly internal to the company such as a storereplenishment orders, and others). In some embodiments described herein,an example method of order fulfillment includes: causing a first mobilerobot to engage with and transport a mobile storage unit, causing asecond mobile robot to engage with and transport a sellable unitcontainer to a robotic picking cell, causing a third mobile robot toengage with and transport an outbound container to the robotic pickingcell, and causing a picking robot to transfer sellable units from thesellable unit containers to the outbound container.

FIG. 1 depicts a highly-simplified schematic diagram illustrating anexample order fulfillment process 100. The order fulfillment process 100may take place at a variety of different types of facilities such as,but not limited to, flow centers, distribution centers, warehouses,inventory storing locations, order fulfillment centers, receive centers,stores, cross-docking facilities, material handling facilities, and thelike, and combinations thereof. In this disclosure, the term “flowcenter” may be used to refer to any and all such different types offacilities, and combinations thereof. In some examples, the orderfulfillment process 100 takes place at a single facility. Alternatively,in some examples execution of the order fulfillment process 100 isdistributed across two or more facilities. A flow center as describedherein can be a portion of a multi-echelon supply chain.

The flow of sellable items within the overall order fulfillment process100 is driven by demand for those sellable items from customers 110. Inthis disclosure, the term “customers” will be used to broadly refer to avariety of different entities such as, but not limited to, individualconsumers, retail stores (e.g., for stock replenishment), businesspartners, other flow centers, and the like.

Tangible orders 120 result from the demand for sellable items from thecustomers 110. An individual order 120 may be for one unit of a singlesellable item, for multiple units of a single sellable item, for two ormore different types of sellable items, for a case quantity, for apallet load, and the like, and any and all possible permutationsthereof. Whatever the order 120 includes, the goal of the orderfulfillment process 100 is to ship (preferably in a single shipment) allof the sellable items included in the orders 120 in a timely andaccurate manner. However, the scope of the order fulfillment process 100also includes partial shipments that do not include all of the itemsincluded in an order 120.

The orders 120 are entered into an order fulfillment control system 180(represented in FIG. 1 by the dashed-line boundary). In some examples,the order fulfillment control system 180 may be part of and/or maycomprise a business management system such as, but not limited to, anenterprise resource planning (ERP) system, a materials managementsystem, an inventory management system, a warehouse management system,one or more automation control systems, and the like, and combinationsthereof. Accordingly, the order fulfillment control system 180 (orsimply “control system 180”) can, in some cases, broadly encompassmultiple systems that can be situated locally, remotely, or situatedboth locally and remotely. The control system 180 can include hardware,software, user-interfaces, and so on. For example, the control system180 may include one or more computer systems, data storage devices,wired and/or wireless networks, control system software (e.g., programs,modules, drivers, etc.), user interfaces, scanners, communicationmodules, interfaces for control communications with robots, and thelike. Such scanners may include hand-held, mobile, and/or fixed readersthat can scan, receive, or otherwise detect marks or tags (e.g., barcodes, radio frequency identification (RFID) tags, etc.) on individualsellable items or collections of sellable items (e.g., cases and totes)and communicate with a control station or stations of the control system180. The scanners may also be able to scan, receive, or otherwise detectthe marks or tags (e.g., bar codes, RFID tags, etc.) attached to orintegrated with conveyance receptacles such as inventory totes andboxes.

Still referring to FIG. 1, incoming shipments of items 140 arrive at theflow center. In some cases, the incoming shipments of items 140 areprocessed by receiving 144 (e.g., the performance of inspections,quantity confirmations/reconciliations, inventory/order control systemtransactions, etc.). Afterwards, the items enter into inventory 150 ofthe flow center as sellable units. In some cases, some incoming items godirectly from receiving 144 into inventory 150 (e.g., if the incomingitems were transferred in from an affiliated facility at which the itemswere already in the inventory system). The types and quantities of theincoming items 140 may be controlled to keep a desired stock level ofthe sellable units in the inventory 150 of the flow center. In somecases, the types and quantities of the incoming items 140 may be theresult of a proactive inventory transfer (e.g., “pushing” inventory), areactive inventory transfer (e.g., “pulling” inventory), and/or othersuch inventory management techniques.

The sellable units in inventory 150 can be located in various types ofstorage accommodations such as racks, shelves, containers, vessels,carts, bins, totes, pallet lanes, and the like. Such storageaccommodations can be individually identified and tracked by the controlsystem 180. That is, the control system 180 can be used to keep track ofthe quantities in stock of the various sellable items in the inventory150 and of the inventory location(s) of the various sellable items inthe inventory 150. The sellable items in the inventory 150 can be storedin various receptacles such as, but not limited to, boxes, totes,pallets, baskets, bins, bags, and the like.

Next, in the step of order assemblage 160, the sellable item(s) includedin the customer order 120 are compiled in preparation for shipment tothe respective customer 110. To fulfill the customer orders 120, the oneor more items specified in each order may be retrieved, or picked, frominventory 150. Picked sellable items may be delivered or conveyed to oneor more areas in the flow center for sorting and assembling into one ormore outbound shipping containers for the fulfillment of a respectivecustomer order 120. Outbound shipping containers containing the orderedsellable items are then transported to customers 110 at the step ofshipping 170.

FIG. 1 and the foregoing description of the order fulfillment process100 has provided a high-level overview of the operations of a flowcenter. Next, in reference to FIG. 2, a much more detailed descriptionfocused particularly on the steps of inventory of sellable units 150 andorder assemblage 160 will be provided.

FIG. 2 depicts a flowchart of an example order fulfillment process 200in accordance with some embodiments described herein. It should beunderstood that any of the concepts, systems, methods, and contextsdescribed above in reference to the order fulfillment process 100 canalso analogously apply to the order fulfillment process 200. Forexample, while not specifically depicted in FIG. 2, it should beunderstood that the operations of the order fulfillment process 200involve the use of an order fulfillment control system (such as awarehouse management system, one or more computerized automation/roboticcontrol systems, and/or other such systems that can communicate andcoordinate control activities between each other and across the overallorder fulfillment process 200). Such an order fulfillment control systemcan be situated locally, remotely situated, or both locally situated andremotely. From an overview standpoint, the order fulfillment process 200begins with inventory storage at step 210 and ends with the transfer ofcompleted outbound containers to be shipped to customers for thefulfillment of customer orders at step 250. Order fulfillment process200 includes the daily replenishment and movement of inventory generatedfrom real-time demand singles for in-store retail sales anddirect-to-guest on-line sales fulfilled from a multi-echelon inventoryholding model at the correct unit of measure, using fast and easymaterial handling equipment that will create operational efficiency atevery process step in the supply chain.

It should be understood that order fulfillment process 200 allowsmultiple types of orders to be processed and fulfilled using the same(or essentially the same) order fulfillment process 200. For example,direct-to-customer shipments, store replenishment orders, customerpick-up-at-store orders, forward deployment of inventory shipments,inventory transfers (e.g., proactive inventory transfers, reactiveinventory transfers), and the like can be processed and fulfilled usingessentially the same order fulfillment process 200. Hence, the orderfulfillment process 200 can be considered as a type of omni-channelorder fulfillment process.

The flow center's inventory of sellable units can be stored in denseinventory storage 210. In some examples, the dense inventory storage 210includes a plurality of robotically-movable mobile storage units thatare densely consolidated in one or more areas of the flow center. Insome examples, the dense inventory storage 210 includes a plurality ofmanually-movable mobile storage units that are densely consolidated inone or more areas of the flow center. In particular examples, the denseinventory storage 210 includes a combination of: (i) robotically-movablemobile storage units and (ii) manually-movable mobile storage units thatare densely consolidated in one or more areas of the flow center. Themobile storage units can be any type of storage unit such as, but notlimited to, racks, shelves, totes, carts, bins, cases, cartons, boxes,containers of other types, and the like, and combinations thereof. Insome examples, a pallet can be used as for a mobile storage unit.

Each mobile storage unit of the mobile storage units in the denseinventory storage 210 defines one or more storage locations in whichinventory of sellable units can be stored and retrieved/picked from. Forexample, without limitation, a single mobile storage unit (e.g., tote orcarton) may define one, two, three, four, five, six, seven, eight, nine,ten, eleven, twelve, fourteen, sixteen, eighteen, twenty, twenty-two,twenty-four, or more than twenty-four individual storage locations inwhich a particular sellable unit may be stocked in a homogeneous manneror in a heterogeneous manner. That is, in some cases, but notexclusively, the inventory storage locations can be used to store asingle sellable unit or sellable unit container that is a homogeneoussellable unit container (e.g., a carton or box containing one and onlyone type of sellable unit). Alternatively, in some cases, a singlesellable unit container that is stored in the inventory storage locationis a heterogeneous sellable unit container (e.g., a carton or boxcontaining two or more different types of sellable units that aredivided from each other by a physical barrier). In some cases, suchheterogeneous sellable unit containers may contain two or more differenttypes of sellable units that are not divided from each other by aphysical barrier. The term “inventory tote” can be a mobile storageunit, and can be understood to encompass all such sellable unitcontainers (e.g., sellable unit containers that are homogeneous as wellas sellable unit containers that are heterogeneous (and with or withoutphysical barriers)). A particular mobile storage unit that defines twoor more storage locations may have a same type of sellable unit in eachof its storage locations, or may have differing types of sellable unitsin its storage locations.

In some cases, an inventory tote is used to hold multiple sellable itemsthat have been decanted from a vendor's original full case packaging. Inother cases, an inventory tote can be used to hold one or more originalfull case packages of a vendor (each full case package holding aquantity of one or more sellable items), and orders for full cases ofone or more items can thereby be fulfilled.

In some cases, the inventory totes are autonomously loaded intorespective storage locations of the mobile storage unit in the denseinventory storage 210. Devices and systems such as conveyors, robots,and/or other types of material handling equipment can be used to performthe autonomous loading. In some cases, the inventory totes are stored inthe dense inventory storage 210 without being located on a shelf orrack.

The mobile storage units of the dense inventory storage 210 are movableby mobile robots in some embodiments. That is, each individual mobilestorage unit can be transported within the flow center by a mobile robotthat is adapted to releasably engage with and transport the mobilestorage unit. Such actions can be initiated and controlled by thecontrol system(s) that is/are involved with the execution of orderfulfillment process 200. In some embodiments, the mobile storage unitsof the dense inventory storage 210 are movable manually and/or by amobile robot.

Because the mobile storage units of the dense inventory storage 210 are,in some examples, movable by mobile robots, the mobile storage units canbe densely consolidated. Accordingly, floor space within the flow centerfor inventory storage can be conserved. That is, for example the needfor space to allow for traditional material handling equipment like forktrucks, pallet trucks, conveyors, and the like, is reduced because themobile robots can store the mobile storage units compactly in the denseinventory storage 210.

In some embodiments, the system and/or area making up a portion of, orall of, the dense inventory storage 210 can comprise an automated totestorage and retrieval system with integrated mobile robots, an automaticstorage and retrieval system (ASRS), a three-dimensional storagegrid/matrix with integrated mobile robots, flow-through racking, and thelike, and combinations thereof. The dense inventory storage 210 can bethree-dimensional to facilitate multi-level vertical storage. Moreover,aisle space of the dense inventory storage 210 can be minimized oreliminated by the use of some such systems. In some embodiments, suchsystems can be used to automatically, or semi-automatically, transferthe mobile storage units to one or more physical output points/locationsfor transport by, or to, the next step of the order fulfillment process200 or to a conveyance system, for example.

In some embodiments, the dense inventory storage 210 is a singleall-in-one system. In some embodiments, the dense inventory storage 210is comprised of two or more modules of a particular type of system, orof two or more different types of systems.

Sellable unit demand in the form of a customer order 212 is received bythe control system of the flow center. The customer order 212 can be ofvarious types such as, but not limited to, a direct ship-to-customerorder, a store replenishment order, a pre-emptive placement of inventoryorder (e.g., to another flow center, to a backroom of a store asforward-deployed inventory, etc.), and the like. In some cases, a storereplenishment order or pre-emptive placement of inventory order can beresponsive to a customer sale at a store. Accordingly, such an order canbe a real-time, demand-based order. It should be understood that theorder fulfillment process 200 facilitates, in a consolidated manner, thefulfillment of ship-to-customer orders, the fulfillment of storereplenishment orders, the fulfillment of customer pick-up-at-storeorders, the fulfillment of forward deployment of inventory shipments,the fulfillment of inventory transfers, and the like, using the samefulfillment systems and processes.

At step 214 of the order fulfillment process 200, in some embodimentsthe control system causes a mobile robot to move to and engage with aparticular mobile storage unit (in the dense storage area or from anoutput location of the dense storage area) that is storing an inventoryof one or more sellable units that are included in the customer order212. The mobile storage unit may be a tote, carton, pallet, etc., or arack with multiple totes, cartons, etc. After engaging with theparticular mobile storage unit, the mobile robot autonomously transportsthe mobile storage unit to the que of a robotic item picking cell, or toan extraction area of the flow center. At the extraction area of theflow center, the inventory tote containing the sellable unit(s) that isincluded in the customer order 212 is removed from the storagelocation(s) of the mobile storage unit, as needed.

The removal of the inventory tote containing the sellable unit that isincluded in the customer order 212 from the storage location(s) of themobile storage unit at the extraction area can be performed in variousways. For example, in some cases the removal can be performed by a robot(e.g., the same robot that transported the mobile storage unit, or adifferent robot). In some cases, the removal can be performed by othertypes of autonomous devices/systems. In some cases, the removal can beperformed manually by a worker. In some cases the mobile storage unit isan inventory tote, and extraction is not required.

Also at step 214, after the inventory tote is removed from the mobilestorage unit if so needed, in some examples the inventory tote thenbecomes engaged with another mobile robot. In this scenario, the mobilerobot is engaging with and transporting a single inventory tote (ascompared with the mobile robot mentioned above that can engage with andtransport an entire mobile storage unit that may include two or moreinventory totes/cases). In some scenarios, the inventory tote istransported by the mobile robot mentioned above.

Step 214 can, alternatively or additionally, encompass the transfer(e.g., using a mobile robot) of a single inventory tote/case from thedense inventory storage 210 (as an alternative to robotically moving amobile storage unit of two or more homogenous totes/cases to theextraction area). In such a case, the mobile robot that transfers thesingle inventory tote/case from the dense inventory storage 210 can alsobe used (but need not be used in every scenario) to facilitate furthertransfers of the single inventory tote/case as described in the nextsteps.

Next, at least two different paths can be taken depending on whether theinventory tote containing the sellable unit that is included in thecustomer order 212 is a tote or a full case of sellable items. If a fullcase has been ordered by the customer order 212, the mobile robot willtransport the full case to the outbound buffer area of the flow centeras identified in step 238. The outbound buffer will be explained infurther detail below. If the sellable unit that is included in thecustomer order 212 is contained in an inventory tote, the inventory toteis transported by the mobile robot to a queue of a robotic picking cellas identified in step 216.

At step 216, one or more inventory totes are in a queue awaitingprocessing by a picking robot in the robotic picking cell (as per step230 described below). While in the queue at step 216, in some examplesall of the inventory totes can remain engaged with a respective mobilerobot. Alternatively, in some examples only some (or none) of theinventory totes remain engaged with a mobile robot while in the queue.

At step 218, empty outbound boxes/totes that will receive sellable itemsfor shipment are in a queue awaiting processing by the picking robot inthe robotic picking cell (step 230). While in the queue at step 218, insome examples all of the empty outbound boxes/totes remain engaged witha respective mobile robot. Alternatively, in some examples only some (ornone) of the empty outbound boxes/totes remain engaged with a mobilerobot while in the queue. It should be understood that the shippingcontainers for both direct-to-customer orders and for storereplenishment orders are staged here at step 218 together in the samequeue. In some cases, this mixing of direct-to-customer orders and storereplenishment orders in the same process may allow for greaterutilization of the robotic picking cell process in comparison toprocessing only one or the other of direct-to-customer orders or storereplenishment orders.

In steps 220 and 222, the sequence that will be followed as theinventory totes from step 216 and the outbound boxes/totes from step 218are processed by the picking robot in the robotic picking cell (step230) is optimized by the control system of the flow center, the controlsystem of the robotic picking cell, the mobile robot storage controller,another control system, and/or any combination thereof. The optimizationof the picking process sequence can be performed by the control systemon a periodically-repeated and frequent, on-going basis. It should beunderstood that this particular aspect allows the order fulfillmentprocess 200 to be highly flexible, agile, responsive, and efficient.That is, the prioritization of certain customer orders 212 over othercustomer orders 212 can take place up to the very last moment prior tobeing processed in the picking cell. For example, using thisfunctionality of the order fulfillment process 200, a high priorityorder can expediently “jump to the front of the line” ahead of otherlower priority orders. As another example, an incomplete box/tote thatis awaiting one or more additional sellable items that are notimmediately available can be prioritized below others so as to avoidconstraints to the overall flow of the order assemblage process foroutbound shipments. The transportation of the individual inventory totesand outbound boxes/totes by the mobile robots helps facilitate thisability to change the picking cell processing sequence on the fly, andup to the last moment prior to processing in the robotic picking cell.Accordingly, the throughput of the flow center can be optimized, andre-optimized, on an on-going basis so as to best satisfy customerdemands and business needs. In some cases, the control system of theflow center, the control system of the robotic picking cell, the mobilerobot storage controller, and/or other control systems involved in theperformance of the order fulfillment process 200 can utilize machinelearning so as to improve the overall performance of the system overtime.

At step 230, a picking robot transfers one or more of the sellable itemsfrom an inventory tote to an outbound box/tote. In some cases, camerasand/or vision systems are employed to enhance the accuracy and speed ofthe picking robot.

In some examples, step 230 can, alternatively or additionally, comprisea different type of picking process (e.g., different than a pickingrobot as described above). For example, in some cases step 230 isperformed partially or fully manually by one or more workers. In anotherexample, step 230 can be performed partially or fully using atele-operated picking system (e.g., where a human operates one or morepicking machines/processes remotely).

At step 232, after processing in the robotic item picking cell,inventory totes are robotically transferred (by a mobile robot) backinto the queue (step 216), back to dense inventory storage 210, toanother robotic item picking cell, to a replenishment station (adecantation or singulation process station), to a buffer, to a servicearea (e.g., a quality check area, an error-correction station, etc.), orelsewhere as determined by the control system of the flow center, thecontrol system of the robotic picking cell(s), the mobile robot storagecontroller, and/or other control systems involved in the performance ofthe order fulfillment process 200. In some cases, the control system ofthe flow center can determine, facilitate, and control such movements ofthe inventory totes as necessary to optimize the overall efficiency ofthe flow center. It should be understood that, in some cases, thecontrol system of the flow center can encompass and/or communicate withother control systems such as, but not limited to, the control system ofthe robotic picking cell(s), the mobile robot storage controller, andthe like, without limitation.

At step 234, outbound containers that have received one or more sellableitems but need to receive at least one more prior to shipment (a/k/a “anincomplete outbound box/tote”) can be robotically transferred (via amobile robot) back into the queue for the robotic item picking cell(step 218), or to the queue of another robotic item picking cell.

At step 236, boxes that will be shipped directly to a customer arerobotically transferred (via a mobile robot) to a packaging stationarea. This packaging step can include various processes such as, but notlimited to, placement of packing materials (dunnage) in the box, boxsealing, labeling the box, gift-wrapping, and the like.

At step 238, outbound containers for store replenishment orders and/orforward-deployed inventory orders are robotically transferred (via amobile robot) to an outbound buffer area of the flow center.

While step 236 pertains to outbound containers that will be shippeddirectly to customers and step 238 pertains to outbound containers thatwill be shipped to stores, it should be understood that the orderfulfillment process 200 can also be used similarly to prepare outboundcontainers that will be shipped to another type of facility such as, butnot limited to, a warehouse, a distribution center, another flow center,and the like.

At step 240, the sequence of outbound containers for store replenishmentorders and/or forward-deployed inventory orders is optimized by thecontrol system of the flow center. The optimization is performed with aview towards the future arrival at a store of the outbound containers,and more particularly towards optimization of efficiencies related toputting the sellable items from the outbound containers onto storeshelves or into backroom inventory. As one example, two or more outboundcontainers that are destined for stocking a particular same aisle of astore may be positioned next to each other in a trailer of a semi-truckshipment. In addition, the sequence and location of the individual itemsplaced in the outbound shipping containers that are going to stores canbe optimized for efficient store put-away-to-shelves. For example, theitems that will be put into stock locations first can be placed on topof the other units. In another example, the outbound shipping containersthat are going to stores may be subdivided into multiple separatedcompartments for ease of selection when putting the products on theshelves at the store.

At step 250, completed outbound boxes and totes are transferred to theshipping area and loaded into trucks or trailers. In some cases, themobile robots are used to perform the transfer of individual boxesand/or totes. In some cases, the completed outbound boxes can betransferred and loaded manually, or another type of conveyance systemcan be additionally or alternatively used. In all instances, the trailercan be loaded such that multiple destinations can be serviced by thedelivery truck along a particular delivery route with the products foreach destination grouped together in the trailer in reverse sequenceorder of the specific destinations visited along the delivery route.

The order fulfillment process 200 can be considered, in someembodiments, to generally include three process portions: (i) storageand retrieval (steps 210-214), (ii) order sortation (steps 216-234), and(iii) sequencing of outbound containers (steps 236-250). In someembodiments, all three portions of the order fulfillment process 200 areintegrated into an essentially single, all-in-one type of system. Insome embodiments, some or all of the three portions of the orderfulfillment process 200 are separate systems or modules that functionessentially separately, but in conjunction with each other, to performthe order fulfillment process 200.

Particular embodiments of the subject matter have been described. Otherembodiments are within the scope of the following claims. For example,the actions recited in the claims can be performed in a different orderand still achieve desirable results. As one example, the processesdepicted in the accompanying figures do not necessarily require theparticular order shown, or sequential order, to achieve desirableresults. In certain implementations, multitasking and parallelprocessing may be advantageous.

Various implementations of the systems and techniques described here canbe realized in digital electronic circuitry, integrated circuitry,specially designed ASICs (application specific integrated circuits),computer hardware, firmware, software, and/or combinations thereof.These various implementations can include implementation in one or morecomputer programs that are executable and/or interpretable on aprogrammable system including at least one programmable processor, whichmay be special or general purpose, coupled to receive data andinstructions from, and to transmit data and instructions to, a storagesystem, at least one input device, and at least one output device.

These computer programs (also known as programs, software, softwareapplications or code) include machine instructions for a programmableprocessor, and can be implemented in a high-level procedural and/orobject-oriented programming language, and/or in assembly/machinelanguage. As used herein, the terms machine-readable medium andcomputer-readable medium refer to any computer program product,apparatus and/or device (e.g., magnetic discs, optical disks, memory,Programmable Logic Devices (PLDs)) used to provide machine instructionsand/or data to a programmable processor, including a machine-readablemedium that receives machine instructions as a machine-readable signal.The term machine-readable signal refers to any signal used to providemachine instructions and/or data to a programmable processor.

To provide for interaction with a user, the systems and techniquesdescribed here can be implemented on a computer having a display device(e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor)for displaying information to the user and a keyboard and a pointingdevice (e.g., a mouse, a trackball, or a touchscreen, etc.) by which theuser can provide input to the computer. Other kinds of devices can beused to provide for interaction with a user as well; for example,feedback provided to the user can be any form of sensory feedback (e.g.,visual feedback, auditory feedback, or tactile feedback); and input fromthe user can be received in any form, including acoustic, speech,tactile input, eye movement tracking input, a brain-computer interface,gesture input, and the like, and combinations thereof).

The systems and techniques described here can be implemented in acomputing system that includes a back end component (e.g., as a dataserver), or that includes a middleware component (e.g., an applicationserver), or that includes a front end component (e.g., a client computerhaving a graphical user interface or a Web browser through which a usercan interact with an implementation of the systems and techniquesdescribed here), or any combination of such back end, middleware, orfront end components. The components of the system can be interconnectedby any form or medium of digital data communication (e.g., acommunication network). Examples of communication networks include alocal area network (LAN), a wide area network (WAN), and the Internet.

The computing system can include clients and servers. A client andserver are generally remote from each other and typically interactthrough a communication network. The relationship of client and serverarises by virtue of computer programs running on the respectivecomputers and having a client-server relationship to each other.

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of anyinvention or of what may be claimed, but rather as descriptions offeatures that may be specific to particular embodiments of particularinventions. Certain features that are described in this specification inthe context of separate embodiments can also be implemented incombination in a single embodiment. Conversely, various features thatare described in the context of a single embodiment can also beimplemented in multiple embodiments separately or in any suitablesubcombination. Moreover, although features may be described herein asacting in certain combinations and even initially claimed as such, oneor more features from a claimed combination can in some cases be excisedfrom the combination, and the claimed combination may be directed to asubcombination or variation of a sub combination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. In certain circumstances, multitasking and parallel processingmay be advantageous. Moreover, the separation of various system modulesand components in the embodiments described herein should not beunderstood as requiring such separation in all embodiments, and itshould be understood that the described program components and systemscan generally be integrated together in a single product or packagedinto multiple products.

What is claimed is:
 1. An order fulfillment system, comprising: a denseinventory storage system comprising: a plurality of mobile storage unitsconsolidated in an area, each mobile storage unit defining one or morestorage locations; and a plurality of differing types of sellable units,each mobile storage unit containing one or more of a single type of thesellable units; an automated order assemblage system comprising: one ormore first mobile robots that each releasably engage and transport anyindividual mobile storage unit; a plurality of outbound containers; oneor more second mobile robots that each releasably engage and transportany individual outbound container; and a robotic picking cell adapted toreceive: (i) individual first mobile robots transporting an engagedmobile storage unit and (ii) individual second mobile robotstransporting an engaged outbound container, the robotic picking cellcomprising a picking robot configured to transfer one or more individualsellable units from a respective one of the mobile storage units in therobotic picking cell to a respective one of the outbound containers inthe robotic picking cell; and a control system operable, in response toreceiving an order for a particular sellable unit of the sellable units,to: cause one of the first mobile robots to engage and transport aparticular mobile storage unit to the robotic picking cell, theparticular mobile storage unit storing the particular sellable unit; andcause the picking robot to transfer the particular sellable unit into aparticular outbound container.
 2. The order fulfillment system of claim1, further comprising: an automated container transfer system configuredto transfer individual mobile storage units in preparation forengagement of the individual mobile storage units with respectiveindividual first mobile robots.
 3. The order fulfillment system of claim1, further comprising: a conveyance system that inducts the plurality ofmobile storage units to the dense inventory storage system.
 4. The orderfulfillment system of claim 3, further comprising: an automatedcontainer transfer system configured to transfer individual mobilestorage units from the conveyance system to respective individualstorage locations of the dense inventory storage system.
 5. The orderfulfillment system of claim 1, wherein the control system is alsooperable, in response to receiving an order for a particular sellableunit of the sellable units, to: cause one of the second mobile robots toengage the particular outbound container and to transport the particularoutbound container to the robotic picking cell to receive the particularsellable unit from the picking robot.
 6. The order fulfillment system ofclaim 1, further comprising: an outbound buffer area where multiple onesof the outbound containers that are ready for shipment are staged. 7.The order fulfillment system of claim 6, wherein the control system isalso operable to determine an optimized sequence in which the multipleones of the outbound containers that are ready for shipment should beloaded into an outbound trailer.
 8. The order fulfillment system ofclaim 7, wherein the optimized sequence is based on an efficienttechnique for stocking shelves of a retail store.
 9. A method forpreparing for a shipment of an order that includes a first sellableunit, the method executed by a control system in response to receivingthe order, the method comprising: causing a first mobile robot to engagewith a first mobile storage unit of a plurality of robotically-movablemobile storage units located in a dense storage area, each of the mobilestorage units defining one or more storage locations that can eachreceive one or more sellable units, the first mobile storage unitstoring a first sellable unit; causing the first mobile robot totransport the first mobile storage unit to a robotic picking cellcomprising a picking robot; causing a second mobile robot to engage withand transport a particular outbound container to the robotic pickingcell; and causing the picking robot to transfer the first sellable unitfrom the first mobile storage unit to the particular outbound container.10. The method of claim 9, wherein the order also includes a secondsellable unit that differs from the first sellable unit, and wherein themethod further comprises: causing the first mobile robot to transfer thefirst mobile storage unit out of the robotic picking cell; and causing athird mobile robot to engage with a second mobile storage unitcontaining the second sellable unit and to transport the second mobilestorage unit to the robotic picking cell.
 11. The method of claim 10,further comprising: causing the picking robot to transfer the secondsellable unit from the second mobile storage unit to the particularoutbound container.
 12. The method of claim 11, further comprising:prior to causing the picking robot to transfer the second sellable unitfrom the second mobile storage unit to the particular outboundcontainer, causing the second mobile robot to transfer the particularoutbound container containing the first sellable unit out of the roboticpicking cell, and subsequently causing the second mobile robot oranother mobile robot to transfer the particular outbound containercontaining the first sellable unit to the robotic picking cell.
 13. Themethod of claim 11, further comprising: prior to causing the pickingrobot to transfer the second sellable unit from the second mobilestorage unit to the particular outbound container, causing the secondmobile robot to keep the particular outbound container containing thefirst sellable unit in the robotic picking cell during: (i) the causingthe first mobile robot to transfer the first mobile storage unit out ofthe robotic picking cell and (ii) the causing the third mobile robot totransport the second mobile storage unit containing the second sellableunit to the robotic picking cell.
 14. An order fulfillment system,comprising: a plurality of sellable unit containers; a plurality ofdiffering types of sellable units, each sellable unit containercontaining one or more of a single type of the sellable units; aplurality of outbound containers; one or more mobile container robotsthat each releasably engage and transport any individual sellable unitcontainer or any individual outbound container; and a robotic pickingcell comprising a picking robot configured to transfer one or moreindividual sellable units from a respective one of the sellable unitcontainers in the robotic picking cell to a respective one of theoutbound containers in the robotic picking cell.
 15. The orderfulfillment system of claim 14, wherein the robotic picking cell isadapted to concurrently receive: (i) an individual mobile containerrobot transporting an engaged sellable unit container and (ii) anindividual mobile container robot transporting an engaged outboundcontainer.
 16. The order fulfillment system of claim 14, furthercomprising: a plurality of robotically-movable mobile storage units,each mobile storage unit defining multiple storage locations, eachsellable unit container located in a respective one of the storagelocations.
 17. The order fulfillment system of claim 16, furthercomprising: one or more mobile robots that each releasably engage andtransport any individual mobile storage unit.
 18. The order fulfillmentsystem of claim 16, further comprising: an automated container transfersystem configured to transfer individual sellable unit containers fromthe mobile storage unit in preparation for engagement of the individualsellable unit containers with respective individual mobile containerrobots.